Nevirapine Antiviral Activity in High Viral Loads

Richard Pollard, from the University of Texas Medical Center, reported at Lisbon on a sub-study of a larger international study of about 2,200 patients (Boerhinger Ingelheim 1090 study). The larger study was a randomized, double-blind, phase III clinical endpoint study looking at AIDS progression events or death. In the larger study treatment-nave and experienced patients were randomized to NVP with NRTIs including 3TC or NRTIs alone including 3TC.

The sub-study looked only at individuals who were treatment-nave or had less than 28 days of any anti-retroviral therapy, They all received NVP+AZT/3TC or AZT/3TC with NVP placebo. In the sub-study they evaluated the NVP triple regimen in high viral load patients. About 80% of participants were from South Africa so about 55% were black and 41% white. Mean age was 35 years.

The sub-study is concerned with 154 more advanced patients: median 85 CD4s and 5.3 log viral load at baseline (194,000 copies/ml). 58% (n=90) of patients had above 100,000 copies/ml, and 75% (n=115) had above 50,000 (See Table 1):  

Table 1. Baseline Viral Load - NVP High Viral Load Study

 

NVP (n=74)

NVP-placebo (n=80)

>100,000

54%

68%

>250,000

45%

38%

>500,000

32%

23%

Response of those with High Baseline Viral Loads.
At week 48, the proportion of Patients below 50 copies/ml ITT follows. The numbers were small for those above 500,000. 42% with below 100,000 (21/36) had below 50 copies/ml, and 17/38 (55%) with above 100,000 copies/ml had below 50 copies/ml at week 48. About 50% in the NVP arm remained below 50 copies at week 64. Pollard said there was no statistical relationship at week 48 between baseline viral load and drop in viral load on therapy. CD4 increased about 120 in NVP arm after 1 year compared to 50 CD4 increase in AZT/3TC arm at 1 year (See Table 2):

Table 2. %<50 copies ITT at Week 48

 

NVP

Placebo

>100,000

55%

0%

>500,000

54%

0%

Overall

49%

0%